84 



SUBSTANCES SOLUBLE IN WATEB. 



apparatus recommended by Schulze ^ (Fig. 3), a weighed quantity 

 of powdered ahiminium added, and sohition of caustic soda slowly 

 run ill ; from the deficit in the amount of hydrogen yielded the 



nitric acid present may be calculated. The following are the 

 details of the operation : 



A measured quantity of solution of caustic soda is introduced 

 into the pear-shajied flask B. The end of the glass-rod c is 

 accurately ground into the delivery-tube of B, so that no soda 

 can escape into A until the rod c is raised. The tube C is 



^ Zcitschr, f. anal. Chem. ii. 379, and vi. 379. 



